This counts the total number of packets transmitted over the EOBC, or Ethernet Out-of-Band Channel, a separate lower-bandwidth path used alongside the main VSL data path for certain control traffic. An admin cares because EOBC traffic being present confirms this secondary out-of-band channel is actively carrying traffic, which matters when the primary VSL path is degraded. For example, during a VSL link issue, checking whether this counter continues to increment helps confirm whether the out-of-band channel is still keeping the two chassis synchronized.